气相色谱法测定甲氰·乐果20%乳油的研究

[目的]研究在同柱条件下甲氰.乐果20%乳油中乐果和甲氰菊酯分离测定方法,为企业生产的质量控制和质检机构质量检测提供参考。[方法]以5%OV-101色谱柱固定相,邻苯二甲酸正戊酯为内标物,利用FID检测器通过程序升温方法对甲氰.乐果20%乳油中2种组分进行气相色谱分离和测定。[结果]甲氰.乐果20%乳油中2种组分、杂质得到有效分离,乐果和甲氰菊酯的标准偏差分别为0.049、0.045;变异系数分别为0.30%、1.07%;回收率分别为99.43%~101.07%、99.50%~100.67%;线性相关系数分别为0.999 6、0.999 8。[结论]采用该方法测定甲氰.乐果20%乳油2种有效成分的质量分数,分离效果好,准确度、精密度高,线性关系好,符合定量分析要求。     

乐果液相色谱与气相色谱检测方法的比较

摘 要：【研究目的】通过应用液相色谱法（HPLC）和气相色谱法（GC）对乐果测定的参数进行比较,为乐果检测方法的选择提供参考。【方法】分别应用气相色谱和高效液相色谱法对乐果检测条件进行优化,对这两种测定方法的灵敏度、线性相关性、稳定性及添加回收率的等参数测定结果进行比较。【结果】用液相色谱法测定乐果最低检测限为0.01mg/L,比用气相色谱法（最低检测到0.1mg/L）测定时有更高的灵敏度;HPLC检测（r＝0.9990）较GC（r＝0.9937）有更好的线形相关性;在乐果浓度低于0.1mg/L时,用液相色谱法对乐果进行测定有很好的稳定性,在浓度高于0.1mg/L,两种测定方法的稳定性相当。【结论】用液相色谱法测定乐果完全可以达到农药登记残留试验准则的要求,它比气相色谱法更适合乐果的微量及常量的检测。     

乐果液相色谱与气相色谱检测方法的比较

[研究目的]通过应用液相色谱法(HPLC)和气相色谱法(GC)对乐果测定的参数进行比较,为乐果检测方法的选择提供参考.[方法]分别应用气相色谱和高效液相色谱法对乐果检测条件进行优化,对这两种测定方法的灵敏度、线性相关性、稳定性及添加回收率的等参数测定结果进行比较.[结果]用液相色谱法测定乐果最低检测限为0.01mg/L,比用气相色谱法(最低检测到0.1mg/L)测定时有更高的灵敏度;HPLC检测(r=0.9990)较GC(r=0.9937)有更好的线形相关性;在乐果浓度低于0.1mg/L时,用液相色谱法对乐果进行测定有很好的稳定性,在浓度高于0.1mg/L,两种测定方法的稳定性相当.[结论]用液相色谱法测定乐果完全可以达到农药登记残留试验准则的要求.它比气相色谱法更适合乐果的微量及常量的检测.     

应用花椒凤蝶核型多角体病毒防治花椒凤蝶的试验

在肥城县北山区,用花椒凤蝶核型多角体匀浆液(1.2×10~6多角体/毫升)喷雾,防治花椒凤蝶幼虫,经小区和较大面积试验示范(15和13天后调查),虫口下降率分别为84.9和81.8％;用该病毒与乐果混施,虫口下降率分别为89.3％和86.5％。混施区单株产量高于单施病毒区,两者混用除防治了凤蝶外,还控制了蚜虫的危害。     

乐氰乳油对长足大竹象的防治试验

利用农药乐氰乳油对慈竹长足大竹象Cyrtorachelus buqueti进行了室内和室外防治试验。结果表明施药浓度为300-600倍液，竹笋的成竹率从50％提高到75．9％～76．7％，显示了乐氰乳油对长足大竹象具有较好的防治效果。     

茶皂素对乐果防治菜缢管蚜的增效作用

试验分别测定了不同浓度的茶皂素、乐果及茶皂素与乐果混剂对菜缢管蚜的毒力。结果表明,茶皂素本身对菜缢管蚜的毒力很低,但其对乐果有极显著的增效作用。同浓度的乐果药液凡是加入了茶皂素的处理蚜虫死亡率均明显比未加的单剂高。２４小时测定乐果单剂、乐果＋５００ｍｇ／Ｌ茶皂素（ＴＳ）和乐果＋１０００ｍｇ／ＬＴＳ处理的ＬＣ５０分别为４０．１５、３２．８７和１８．５９ｍｇ／Ｌ;而４８小时测定的ＬＣ５０则分别为１５．３３、１０．１１和７．７７ｍｇ／Ｌ。     

Fenton试剂降解含有机磷农药废水的研究

[目的]寻求一种有效降解含有机磷农药废水的方法。[方法]研究了Fenton反应的反应时间、pH值、H2O：与Fe2＋浓度对降解率的影响,同时考察了光和超声波对反应的促进作用。[结果]对于125mg／L的乐果溶液,在温度60℃,溶液pH值为3,H2O2加入量为5mmol／L,FeSO4·7H2O加入量为0．3g条件下,30min内降解率可达100％,延长反应时间为8h,COD去除率可达100％。光与超声波对Fenton试剂有很强的协同催化作用,3h内COD去除率可达90％。[结论]Fenton试剂可使有机磷农药有效降解。     

氰戊菊酯和乐果在不同作物上的残留降解

本文报道了氰戊菊酯和乐果在不同作物上的消解动态。研究结果表明,上述二种农药在小麦、鸡毛菜、桃子上的起始残留浓度和降解速度都不同,起始残留浓度依次为麦叶>鸡毛菜>麦穗>桃子,这主要与作物比表面积有关,氰戊菊酯的降解半衰期在鸡毛菜上为1.98天、麦穗为5.21天、桃子为7.19天、麦叶为11.65天,乐果在鸡毛菜上的半衰期为0.95天、麦穗为1.85天、麦叶为1.93天、桃子为4.48天。在其他条件基本一致时,农药降解半衰期与作物的生长系数有很大关系。     

Dimethoate induced biochemical perturbations in rat pancreas and its attenuation by cashew nut skin extract

The significant antiradical activity of cashew skin extract was previously described. In this investigation, the extent of protection offered by cashew nut skin extract (CSE) against the damage induced in rat pancreas by sub chronic doses dimethoate (DM), an organophosphorous pesticide was studied. Rats were supplemented with CSE at 20 mg/kg b.w./d after a daily dose of DM at 40 mg/kg/d b.w. for 2 months. Weekly random blood glucose, oral glucose tolerance test (OGTT); pancreatic damage markers like amylase and lipase; oxidative damage markers such as reactive oxygen species generated, extent of lipid peroxidation, host antioxidant defenses like reduced glutathione (GSH); GSH-dependent enzyme activities viz., glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR); free radical scavenger enzymes viz., catalase and superoxide dismutase (SOD); xenobiotic metabolizing enzymes like DT-diaphorase and NADPH-diaphorase were measured in the four different groups namely (1) control, (2) DM treated, (3) CSE supplemented, (4) CSE supplements following DM treatment. Random blood glucose levels increased significantly on exposure to DM compared to that in control rats (119 ± 5 mg/dl vs. 92 ± 4 mg/dl), while the blood glucose levels in CSE supplemented rats were comparable to that of controls. DM treated rats exhibited impaired glucose tolerance at the end of two months as indicated by OGTT, while DM treated rats with CSE supplements showed normal glucose tolerance. Pancreatic specific marker enzymes like amylase and lipase in serum were restored to normalcy in rats supplemented with CSE following treatment with DM which otherwise was increased in the DM treated rats. Distinctly lower levels of GSH, increased levels of ROS, higher extent of lipid peroxidation, along with alterations in antioxidant enzymes and increase in xenobiotic metabolizing enzymes were evident in pancreas of DM treated rats. However, CSE supplement ameliorated the biochemical alterations in the pancreatic milieu in DM treated rats. Treatment with CSE significantly protected rat pancreas from injury, thus ameliorating and restoring tissue antioxidant status and also conferring normal glucose tolerance. The active components present in cashew skin extract can perhaps be effective in reducing the extent of pancreatic injury and in overcoming tissue damage caused by exposure to dimethoate.